Congratulations on your impending Yorkie-mommyhood! You are going to LOVE this breed. Mine captured my heart the very first time I saw him and I just love him more each day!
As for picking a pup -- yes, health and looks are important, but also temperment. When you go to look at a litter of pups, observe how they interact with you and their energy level. Ideally, you don't want a pup who is too shy and/or seems afraid. Doesn't mean he/she won't be a sweet dog, but they may grow to be timid and nervous. It's best to look for the outgoing, alert pup who is curious about you and active. But you probably won't have to worry -- I'm a believer that the puppy that is supposed to be yours will pick YOU! Mine certainly did (it didn't hurt his chances that he put on quite a little floor show at the breeder's house, either!)
Hypoglycemia is a big issue for some very young Yorkies -- but there are also several other things they are prone too -- I'd say pick up a book on Yorkies at your bookstore or pet store -- they always have a chapter on all the health issues. (I think I read three or four books before I got Archie!)
The most difficult part for me as a Yorkie owner has been potty training and the fact that Archie is very stubborn and will not come when he is called! We finally got the potty training thing under control (he's piddle pad trained), but he STILL will not come when called (he's almost two!) Oh well! But these annoyances are nothing when I look into those beautiful brown eyes; he's the snuggliest, yummiest, silliest, sweetest little thing in the world and he has really filled a hole in my heart. He's the best!
